Motor controller



Oct. 11, 1921. 1,644,820

' w. DRIVER- MOTOR CONTROLLER Filed April 26. 1926 INVENTOR.

TTORNEYS.

55 thereof.

Patented Oct. 11, 1927.

UNITED STATES.

1,644,820 PATENT OFFICE.

WILLIAM DRIVER, OF RACINEZWISCONSIN, ASSIGN OR TO HAMILTON BEACH MFG. 00., OF RAGINE, WISCONSIN, A CORPORATION OF WISCONSIR.

MOTOR CONTROLLER.

Application filed April 26, 1926. Serial No. 104,858.

This invention relates to improvements in motor controllers, more particularly adapted for controlling sewing machines, dental lathes or other light machinery.

One of the objects of the present invention is to provide a foot operated motor controller which ma be electrically connected to a motor an placed upon the floor and engaged by the foot of the operator, and

as the foot pedal is pressed with greater or less force, the speed of the motor will be correspondingly increased or diminished.

A further object of the invention is to provide a motor controller in which the electric circuit through the controller is opened at a point other than the last terminal contact of the resistance unit toprevent arcing and roughness of the contacts.

A further object of the invention is to provide a motor controller in which the electric circuit is opened at the end of an elongated contact so that any roughness to the movable contact member caused by arcing will be smoothed down by the rubbing of the movable contact member against the elongated contact.

A further object off the invention is to provide a motor controller associated with a resistance unit in such a manner that as the foot treadle is pushed downwardly, portions of the resistance unit will be cut out of the circuit in which they are included, in successive order to control the speed of the motor which is also included in the circuit.

A further object of the invention is to provide a motor controller which is associated with the resistance unit in a unitary structure, which is compact in size, and is simple in construction.

A further object of the invention is to provide a motor controller in'which the contact member is loosely connected to the contact arm in a manner to permit an intimate engagement between the fixed contacts and the slidable member.

A further object of the invention is to provide a motor controller which is of simple construction, is strong and durable, and

is well adapted for the purpose described.

With the above and other objects in view, the invention consists of the improved motor controller and its parts and combinationsas set forth inthe claims, and all equivalents In the accompanying drawing, in which, the same reference characters indicate the same parts in all of the views:

Fig. 1 is atop view of the improved motor controller, portions of the resistance unit casing being removed to show interior construction;

Fig. 2 is a side viewthereof with the easing portion thereof in section;

Fig. 3 is an enlarged view partly in section of the resistance unit and connected parts;

Fig. 4 is a sectional detail view taken on line 14 of Fig. 2;

Fig. 5 is a vertical sectional detail view of the resistance unit; and

Fig; 6 is a sectional detail view of the mova 1e contact member taken on line 6--6 of Fig. 3.

Referring to the drawing, the numeral 8 indicates a base member which is formed of sheet metal and is provided with rubber feet or pads 9. A foot treadle or member 10 is positioned above the base member 8 and is provided with downwardly extending eyed cars 11 which engage and are pivotally connected to the side flanges 8 of the base member 8 by a pivot pin 12. The base member is formed with a depressed portion 13 for receiving the lower end portion of a coiled spring 14 which is interposed between the base member and the foot treadle to yieldingly hold the treadle in its upper position. A U-shaped casing member 15 is mounted on the base member 8 and extends upwardly therefrom, and is formed with edge flanges 16 for receiving a U-shaped piece of screen material 17 which forms the other and ventilating part of the casing.

An L-shaped'bracket 18 is mounted within the casing and extends upwardly therefrom, and has connected thereto an insulating block of material 19 which is formed with a spirally trending groove 20 for receiving the oonvolutions of resistance wire 21, wound thereon. To revent' contact between the wire and the racket 18, the insulating block 19 is formed with a recess 22 to receive the upper portion of the bracket and space said portion from the resistance wire. The upper end portion of the resistance is clamped between the insulating block 19 and a fixed contact stud member 23 which is mounted in the block. Other contact studs 24 engage the resistance wire convolutions in 119 wire 39.

successive order from the upper to the lower riglrtion of the block, as s own in Fig. 3.

e fixed contact studs have reduced diameter shank portions which extend partly through the insulatin block and are rlveted or s read at their end portions, as indicated by t e numeral 26, to securely hold the studs in position. A fixed elongated contact member 27 of U-formation is also mounted on the insulating block 19 in a line parallel to the line of fixed studs and spaced from the convolutions of resistance wire and the studs, as shown in Figs. 3 and 5. The end portions of the elongated fixed contact member extend into the insulating block, and one of said ends is riveted to hold the member in position.

Two insulated studs 28 and 29 are positioned above the elongated contact member 27 and the upper stud 23 to support the movable contact member 30 when in its ofi position. Said movable member is of the oating type to form an intimate electrical contact between the movable member and the fixed contacts, and to accomplish this result, it is provided with a transversely extending slot31 for loosely receivingthe inturned end 32 of the yielding contact arm 33.

The movable contact member 30 is also of angular or ofiset formation, as clearly shown in Fig. 3, so that in moving upwardly to open the circuit, engage the up er end of the elonlgmirited fixed contact 27 an open the circuit t ough the controller before the other portion 30" of the movable contact 30 disengages the fixed contact 23. An roughness to the portion 30' of the mova le contact 30 which might be caused by arcinglwill be quickly worn ofi by the rubbing of t e movable contact on the e on ated fixed contact and thus prevent the roug1 ess extending over an increasing area. T e portion of the arm 33 adjacent the end is indented to form an inturned shoulder' 34 which bears centrally on the movable contact member and permits said member to rock lon 'tudinally and transversely to compensate or the inequalities of the alinement of or the surfaces of the fixed contacts. The opposite end of the arm 33 is connected to an insulating block 35 and said block is firmly mounted on the outer side portion of an upturned guard formed on one side edge of the foot treadle 10, so that when the treadle is pressed downwardly, the resistance will be cut out of the circuit, in which the controller is included in a step by step movement. v

The lower end of the resistance wire is connected to a 0st 36 by a wire 37, and the lower end of t e elongated contact member 27 is connected to the binding post 38 by a Wires 40 provide for connecting the controller a circuit.

the offset edge 30' will dis sistance wire,

From the foregoing description, it will be seen that the motor controller is of very block 35 simple construction, and is well adapted for the purpose described.

What I claim as my invention is 1. A motor controller, comprising a support, an insulating port and having grooves formed therein, a coil of resistance wire included in an electric circuit and wound around the insulating block and extending into said grooves, a line of fixed contacts intersecting portions of the resistance wire, an elongated fixed contact extending in a line adjacent the line of fixed contacts but free from contact with the resistance wire, a circuit wire connected to the elongated fixed contact, a circuit wire connected to one end of the resistance wire, a treadle pivotally mounted on-the sup rt, means for yieldingly holding the tree e in its upper sition, an arm carried by and insulated cm the treadle and having an inturne-d end portion, and a movable contact member enga ing the elongated contact member and t e xed contacts and havin an openin through which the inturned en portion 0 the arm extends to form a freely movable engagement therebetween, said movable contact member disengaging the elongated contact and 0 before it disengages the fixed contact.

2. A motor controller, comprising a support, an insulating block carried by the support and having grooves formed therein, a coil of resistance wire wound around the insulating block and extending into said grooves, a line of fixed contacts mtersectin portions of the resistance wire, an elongated fixed contact extending in a line adjacent the line of fixed contacts but free from contact with the resistance wire, a circuit wire connected to the elongated fixed contact, a circuit wire connected to one end of the rea treadle pivotally mounted on ast resistance wire the support, the treadle in its upper carried by and insulated andhaving an inturned end movable contact member en aging the elongated contact member and tl ie fixed contacts and having a transversel extending elongated opening through w ich the inturned end portion of the arm extends to form a freely movable enga ement therebetween.

3. A motor cont-1'0 er, comprising a support, an insulating block carried by the support .and having a spirally. extending groove formed therein,

sition, an arm om the treadle a coil of resistance wire wound around the block and extending into the groove, a line of fixed contacts intersecting the portions of the resistance at spaced block carried by the supportion, and a ening the clrcuit means for yieldingly holding line of contacts but free intervals, an elon ated fixed contact extending in a line su ntially parallel to the from contact with the resistance wire, a circuit connected to the elongated fixed contact, a circuit wire connected to the lower end portion of the resistance wire, a treadle pivotally mounted on the su port, a coiled spring means for yieldingly holding the trcadle in its upper position, an arm carried by and insulated from the treadle and having an inturned end portion and an inwardl extending medial shoulder, and a movab e contact member engaging the elongated contact member and the fixed contacts and having a trans versely extending opening through which the i nturnedend portion of the arm extends,

the medial shoulder of the arm bearing on the movable contact member to form a freely movable engagement therebetween.

-movable contact member carri and having'edgewi'se ofiset portions whlch 4. A motor controller, comprising a support, an insulating block carried by the support, a resistance carried by the lock and having fixed contacts associated therewith, another fixed contact associated with the block, a treadle pivotally mounted on the support, and arm carried by the treadle and having an inturned end portion, and a floating slotted contact member for pivotally receiving the inturned end ortiori, said by the arm WILLIAM DRIVER. 

